9/11 Memorial Museum commemorates the September 11, 2001 attacks. The memorial is located at the World Trade Center site, the former location of the Twin Towers, which were destroyed during the September 11 attacks. The majority of the building is underground. An entrance ramp leads 70 feet down to a large hall in the footprint of the North Tower, meant to evoke emptiness and absence.
Foundation Hall is a huge, “slurry wall,” a retaining wall that survived the attacks, is incorporated into the design, and is meant to represent survival and determination. This space houses the “Last Column,” a 36-foot-high piece of steel that was the last to be taken from the site during cleanup in May 2002. The museum holds 10,000 artifacts, including wrecked emergency vehicles, 911 phone calls, and emergency response recordings, pictures of all of the victims, and media of the entire event from crash to cleanup. There are also more than 2,000 recordings of first-hand oral history.